It is known that one skilled in the art can blend two or more polymeric materials to achieve beneficial performance characteristics in the resulting polymeric composition. One such conventional blending process is the blending of elastomeric and thermoplastic polymeric materials. For example, U.S. Pat. No. 6,642,316 to Datta, et al. discloses blending ethylene propylene based interpolymers with polypropylene so as to provide a polypropylene dispersed phase and an elastomeric continuous matrix phase. The overall blend may be elastomeric in nature. The ethylene propylene based interpolymers may be of the type described in U.S. Pat. No. 6,525,157 to Cozewith, et al.
Various methods of producing polymeric blends are known. U.S. Pat. No. 6,207,756 to Datta, et al. describes a process for producing a blend of a dispersed phase of a semi-crystalline plastic and a continuous phase of an amorphous elastomer. The blends are produced in series reactors by producing a first polymer component in a first reactor and directing an effluent of the first reactor to a second reactor and producing the second polymer component in solution in the second reactor in the presence of the first polymeric component. U.S. Pat. No. 6,319,998 to Cozewith, et al. also discloses using series solution polymerizations to produce polymer blends. The polymer components of the blends are ethylene copolymers. U.S. Pat. No. 6,770,714 to Ommundsen, et al. discloses the use of parallel polymerizations to produce different polymeric components that are then blended through extrusion of solid finished products or using other conventional mixing equipment. One polymeric component is a propylene homopolymer or copolymer and the second polymeric component is an ethylene copolymer.
U.S. Pat. No. 6,635,715 to Datta, et al. discloses the production of physical polymer blends through blending a first polymer component that is a propylene homopolymer or copolymer and second polymer component that is propylene-alpha olefin copolymer including 5 wt. % to 25 wt. % of the alpha olefin. The polymeric components are blended by mechanical means such as melt pressing.